In recent years it has become a major concern of manufacturers of products designed for human consumption, such as pharmaceutical products, foodstuffs and the like, that the packages be resistant to tampering by individuals bent on the introduction of deleterious substances into the packages. For example, over the past several years there have been several examples of individuals who opened containers on the merchants shelf and introduced substances into the containers, i.e. cyanide and other poisonous substances which ultimately resulted in the death of persons who purchased and consumed the product without any warning that the product had been tampered with. In addition to the unfortunate deaths of the product users, such tampering, or the threat of tampering, has resulted in costly product recalls and loss of consumer confidence in the product and in the manufacturer of the product. As a result of these activities manufacturers and suppliers have been required to adopt relatively expensive measures to seal the product containers and packages in an attempt to protect the product against tampering. Such measures include the use of shrink fit materials over the outer packages as well as over the product containers themselves. Although such measures do provide some degree of protection against tampering, there is a substantial expense involved. For example, it has been estimated that for a bottle of non-prescription pain reliever the cost of attempting to protect against tampering run abougt $0.20-0.40 per bottle.
Accordingly it would be desirable to provide an economical means for sealing the containers of consumable products, which means would provide some protection against tampering and a positive indication that the product container has been opened thereby warning the user that the product may not be safe to use.